I have a 2003 FX4 with a 4.6. A couple of weeks ago, the service engine light came on. The next morning, it developed what I thought was a miss.
I had it checked and was diagnosed as the cam position sensor being bad.
Three cam position sensors later (and two mechanics), the service engine light is still on and symptons are getting worse. Today the mechanic tells me he thinks it is a problem with the main computer. Any suggestions?

 

Sounds like you need a different shop, possibly the dealership even. It's possible to get a bad part, but it doesn't sound like they know how to diagnose the sensor by itself. They can check readings at the plug as well as in the part. Voltages, ohms, all things you check in a pinpoint test. It sounds to me that they're seeing a code for the sensor and that's all they know to do is replace the sensor. That's wrong. It could just be a wiring issue and all the new parts in the world won't fix it. I'd refuse to pay for anything that didn't fix it.